Dale, Sponberg may not
speak disrespectfully, but since he writes of sailors being "insanely conservative" and "blindly acceptant" then it's apparent that he certainly
writes with disrespect.
Re the typical sailors' exposure to "unusual" rigs; many sailors started with an unstayed cat/sprit rig or a gunter
sloop, then moved to a freestanding cat rig, a freestanding lateen cat rig, a conventional
sloop, or an assymetric spinnaker-carrying sloop with a fully battened roachy
mainsail. Where I come from, the most popular two-adult
dinghy has a fully battened roachy main and
jib and a stayed rotating wingmast, whereas the most popular singlehander has an unstayed mast.
So many life-long sailors have switched rigs four or five times before they buy their first yacht, and many of them would never have sailed a 'conventional' rig. It's therefore been proven that they are not scared of "unusual" rigs or changing rigs. That indicates that the choice of a 'conventional' rig for their yachts is not due to conservatism - in fact for a typical British or Australian sailor, the typical yacht rig is something fairly new. If they were conservative, they'd stick with the sort of rig they knew from their
dinghy days and where i'm from that would mean a freestanding rig or a wingmast!
The fact that so many people who have years of
experience with 'unconventional' rigs choose 'conventional' rigs for yachts seems to indicate that their choice is not due to conservatism or lack of experience with 'unconventional' rigs. By the way, personally I prefer less conservative rigs and I'm currently deciding on how to modify the conventional rig on my
new boat; I just respect the choice that others have made.
To get back to the topic (and I apologise for the drift) - if everyone was as conservative in rig choice as some designers claim then 90% or so of cruising boats would still be ketch-rigged like they used to be.